I used mine for removing High-Performance, Racing-Type Valve Springs, but admittedly, I haven't needed to use it all that often, so maybe in time, it would fail or develop issues.

I actually bought Two of this type. One was a lot more stoutly built, better materials, so that's the one I used.

Maybe the Proform Tool would last longer with frequent use?

Is this the Proform Shaft Valve Spring Compressor (or maybe this isn't the correct one)?

http://www.summitracing.com/parts/pro-67460/reviews/

Around $70 - $80.

The one review on Summit Racing, said, quote: "Hard to get keepers back in retainers."

Maybe it was operator skill?